jsp:useBean does more than create an instance of the class. If it finds a bean with the specified name already in the specified scope, it doesn't create a new instance at all -- it just hooks up the existing bean to the scrpting variable. When an instance
is created, it is placed in the specified scope.
This isn't anything you could not do with a scriptlet on the page, but is handier and helps keep
Java scriptlets out of the page.